Joseph lewis mills



(No Model.)

J. L. MILLS- PROCESS OF ENGRAVING ANlj MEZZOTINTING PRINTING SURFACES. No. 424,073. Patented Mar. 25, 1890.

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UNITED STATES PATENT OFFICE.

V JOSEPH LEWIS MILLS, OF BALDWINS GARDENS, GRAYS INN ROAD, COUNTY OF MIDDLESEX, ENGLAND.

PROCESS OF ENGRAVING AND MEZZOTINIING PRINTING-SURFACES.

SPECIFICATION forming part of Letters Patent No. 424,073, dated March 25, 1890.

Application filed March 12, 1889.

Serial No. 303,046. (lTo model.)

T0 at whom it may concern:

Be it known that I, J OSEPH, Lnwrs MILLs, a subject of the Queen of Great Britain and Ireland, residing at Baldwins Gardens, Grays Inn Road, in the county of Middlesex, in that part of the United Kingdom aforesaid called England, have invented a new and improved process of engraving and mezzotinting for the manufacture of surface-printing blocks and intaglio plates for copper and steel plate printing purposes; and I do hereby declare the following to be a true, full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same.

Figure 1 represents a side elevation of the instrument for directinga blast of sand and air against the surface of the stone in accordance with my process. Fig. 2 represents a similar view of a modified form of said instrument,

and Fig. 3 represents a similar view of another modification.

In said drawings, a designatesa metallic or other rigid tube in shape like a pencil, and

provided with a nozzle 1), throughwhich air and provided with a nozzle Z). This tube may be arranged vertically, as shown in Figs. 1 and 3, or -it may be parallel to the tube a, as shown in Fig. 2. these tubes, as shown in Fig. 1, to hold the nozzles in proper position. In this figure the sand-tube is also shown provided with perforatedbulbs or enlargements Z Z the purpose of which is to prevent the clogging of the sand. The air-tube a may be provided with a controlling-valve j, governed by a thumblever 72, which is pivoted to said air=tube at t' and actuated by a spring 70. The instrument is preferably supplied with a handle-strap Z,

for ease of carrying this strap being attached.

to the sand-tube.

In Fig. 3 the nozzle 1) is not exterior to b, as in the other figures, but enters it from the large end, so that they have a common axis. The nozzle 1') has a branch 0, on which fits the flexible pipe 0', leading to the sand-reser- Braces c 0 may connect voir. A plug 1), perforated at the sides, is introduced within this branch and the proximate end of the tube 0 to regulate the outflow of sand. 5 5

WVhichever form be employed the blast of air through nozzle 1) drives the sand issuing from nozzle 12 against the surface to be operated on, producing the results hereinafter described.

The instrument above described is fully set forth and its operation explained in my applioation, No. 295,360. I do not claim it here because said application contains claims on it, and because this present application is for patent on the process only. In carrying into practice that portion of the invention which relates to intaglio engraving I place upon the surface which I propose to engrave a tracing of the picture required, and then stop out in an artistic manner with a suitable varnish or gum or other resisting medium the highest lights of the picture. When the varnish, gum, or other resisting medium has dried,l subject the surface so treated, as aforesaid, to the action of a blast of sand, emery, glass, or other suitable substance composed of more or less fine grains or particles and applied in a suitable manner, hereinafter described, the blast of the finest grains or particles of the material employed being applied first, generally speaking, to produce the finest tints. Afterward I again stop out in anartistic manner with a suitable resisting medium all the parts which I require to be of a strength of tint next to the high lights and apply the blast composed of stronger or coarser grains of the material employed than the blast theretofore applied, and thereby preserve the first light tint wherever it is stopped 0 out. I repeat this process of stopping out and then subj ecting to the blast composed of grains or particles of the material employed of varying size and impelled by a jet of air or steam or water of such varying degree of 5 pressure as may be necessary to drive with more or less force the coarser or finer grains or particles of the said material so working from the high lights to the dark color; or, if the work necessitates it, I place the tracing of the picture upon the surface to be engraved, and I reverse the order of operations by first employing the blast so as to produce the darkest parts of the picture, and afterward by the necessary stoppings out and applications of suitable blasts I complete the system or process hereinbefore described, so working from the black color to the high lights. I also, after placing on the plate a tracing of the required picture, (sayin this instance a tracing of a photograph of an individual,) use as a free hand-tool an instrument or apparatus, hereinafter described, called an air or steam pencil, which is manipulated by the artist and by which he controls the action of the blast.

Theprocess first hereinbefore described has reference to high-class artistic intaglio engraving produced by the fac-simile stopping out by hand or brush and subsequent engraving by the blast, as aforesaid, of the work or feeling contained in any given picture, and thereby producing the artistic handling of the same. I do not confine myself solely to the separate use of eitherof the processes I havedescribed, as the picture or portrait can be completely finishedby combining the several. means hereinbefore mentioned in the production of any given picture.

In carrying into practice that portion of my invention which relates to relief surfaces or typographic printing-blocks I place upon the surface a tracing of the picture required, and then I stop out or draw artistically with a suitable resisting medium the parts which are required to be the blackest in the picture. Afterward I subject the unprotected parts to the action of the blast, thus preserving those parts which have been stopped out-namely, the darkest parts-and tinting those parts which have been left unprotected. I then stop out the next darkest tone to the black, and again subject the block to the action of the blast, thus preserving tone No. 2. This successive treatment I pursue, using more or less fine grains or particles of the material of the blast and more or less force of impact until I come down to the lightest tints of the picture, and so finishingtheblock. I also proceed as follows: I place a tracing of the required picture upon the metal plate and then varnish the whole surface to be engraved with asuitable resistin g medium, or I varnish such surface first and afterward place the tracing upon the resisting medium. Next I draw or etch out with a suitable point or etching-needle all the parts which represent the darkest lines in the picture, and afterward I subject the plate to the action of the blast, which I apply in the manner hereinbefore mentioned. I then draw or etch out in an artistic manner with a suitable point or etching-needle all the other parts of the picturenextin strength of tone to the parts first operated upon and again apply the blast, thereby strengthening the engraved parts and engraving the uncovered or etched parts of'the plate representing drawing No. 2. I repeat the successive operations of drawing oretching out and applying the blast, as hereinbefore mentioned, as often as the exigencies of the work in hand require, with the result-s that the several parts of the engraving are kept in the same relation of depth to each other (although being constantly deepened according to the sequence of the blasts)that is to say, the parts first engraved willbe the deepest, the parts next engraved will be less deep, and so on seriatim, according to the variety and strength of tone which maybe required and from this stage I clear off the whole resisting medium and proceed to obtain the mezzotinting effects of light and shade, and simultaneously fac-simileing the artistic touches in the picture according to my stopping-out system hereinbefore described. I also use photography in the manufacture of typographic printing-blocks, thus: I place a photograph upon the surface to be engraved and then stop out in an artistic manner with a suitable varnish or gum or other resisting medium on the top of the photograph (thereby using such photograph as a tracing and obtaining an extra amount of resistance) the highest lights of the picture, and when the varnish, gum, or other resisting medium has dried I subject the surface so treated to the action of a blast of sand, emery, glass, or other suitable substance composed of more or less fine grains or particles and applied in the manner hereinbefore described,the blast of the finest grains or particles being applied first, generally speaking, to produce the finest tints. Afterward I again stop out in an artistic manner with a suitable resisting medium all the parts of the picture which I require to be of a strength of tint next to the high lights and apply the blast composed of stronger or coarser grains of the material employed than the blast theretofore applied, and thereby preserve the first light tint Wherever it is stopped out. I repeat this process of stepping out and then applying the blast composed of grains or particles of the material employed of varying size and impelled by a jet of air, or steam, or gas, or water of such varying degree of pressure as may be necessary to drive with more or less force the coarser or finer particles of the said material, so working from the high lights to the dark color; or, if the work necessitates it, I reverse the order of operations by first applying the blast so as to produce the darkest parts of the picture, and afterward by the necessary stoppings out and applications of suitable blasts I complete the system or process herei nbefore described, so working from the black color to the high lights. I also use, in the man ner hereinbe'fore described,as a free handtool the instrument or apparatus hereinbeforc mentioned, called an air or steam pencil, with which alone, Without any stepping out, the plate is finished up to the highest tints of the picture.

The several processes hereinbefore mentioned for producing int-aglio and relief sur- IIO faces on typographic blocks of metal areapplicable to the production of such surfaces on blocks of stone, whether lithographic stone or ordinary stone, as I have found that the last-mentioned surfaces lend themselves for being used as printing-blocks. V

I Wish it to be understood that by sandblast I mean every and all processes by which surfaces of metal or stone are engraved or depolished by the percussive force of grains or particlesof sand or such like substance driven by a jet of air, or steam, or gas, or water, or falling by their own gravitation against such surfaces Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is 1. The process of preparing the surfaces m of blocks or plates for plate-printing, conmaterial directed byhand to the point of the surface where needed; fourthly, stopping out with a resisting medium the parts which are to be of strength next to the high lights; fifthly, applying a blast of coarser grains to the surface, this blast being directed as before, and, finally, repeating the steps of stopping out and applying the blast for the lights of lesser strength until the work is complete.

2. The process of engraving on lithographic surfaces, consisting in placing on the surface a tracing of the picture to be engraved and then alternately stopping out certain portions of the picture and applying a sand-blast to it, directed by hand as needed, the parts thus stopped out being successively from lighter to darker or the reverse, and the sand-blasts being successively of finer or coarser material, substantially as described.

In testimony whereof I have hereunto put my hand this 18th day of December, 1888.

JOSEPH Lnwrs MILLS.

Witnesses:

PATRICK OI-IALLORAN, GEORGE SMITH. 

